GIS links

ESRI -- creator of some of the most popular GIS software packages available.

ArcObjects Online -- online documentation for ESRI's ArcObjects.

ArcScripts -- online resource for scripts and extensions written for ESRI products.

Geotools -- an open-source Java toolkit for GIS. Geotools actually consists of two different projects: Geotools 1 & Geotools 2.

Mapserver -- an open-source development environment for building spatially-enabled Internet applications.